Process of manufacturing 5-hydroxyvaleraldehyde



United States Patent QCESS F UFACT- BWG -HYDRQXX- ALERA BEHYDE Joseph B. Dickey and Frederick -B Joyner, Kingsport,

Tenm, .assignors .to Eastman KodakiCompany, Rochester, N- Yaacorp rationof New Jersey e D aw ng- Anrheatien rtemhe .8, 1 .5.

' Serial No. 533,260

This invention relates to improvements in the manufacture of fi hydrpxyvalepaldehyde and flfS-PfilllflflfidjOl by hydrolysis of 2,-3 -dihydropyran, according to the equation:

give a178;2-:% yield .of 5.-.hydroxyvaleraldehyde, and subsequent reduction of the S-hydroxyvaleraldehyde, using a copper chromite catalyst. All of the prior are processes e th mehhfee h s -.P.ehtehe .el requ n the d e s s 9 .2, .l1 ).l .P3 .al. -inf QM he are a di mineral acids, which must be neutralized before isolahlqn of the intermediate S-hydroxyvaleraldehyde or before direct reduction of the product to 1,5-pentanediol On a commercial basis, such procedures would entail expense, and are not readily adaptable to a continuous process.

It is an object of this invention to provide a new and improved process for the production of S-hydroxyvaleraldehyde and 1,5-pentanediol. Another object is to provide a process for the hydrolysis of 2,3-dihydropyran to S-hydroxyvaleraldehyde which entails no loss of catalyst through an expensive neutralization procedure. Another object is to provide a method for the production of S-hydroxyvaleraldehyde which is readily adaptable to a continuous process. A further object is to provide an efficient process for the production of 1,5-pentanediol.

These objects are attained in accordance with this invention by hydrolyzing 2,3-dihydropyran in the presence of an acidic ion-exchange resin and hydrogenating the resulting S-hydroxyvaleraldehyde in the presence of a hydrogenation catalyst.

In the preferred method of practicing this invention, 2,3-dihydropyran is hydrolyzed by heating with water in the presence of an acidic ion-exchange resin. A substantially neutral aqueous solution of S-hydroxyvaleraldehyde is formed. This solution is readily separated from the resin, and is then subjected to hydrogenation in the presence of a hydrogenation catalyst.

The hydrolysis reaction can be carried out continuously by passing an emulsion or solution of the 2,3-dihydropyran in a substantially aqueous medium over the acid ion-exchange resin at an elevated temperature. The required contact time will depend upon the reaction temperature. Batchwise, the reaction can be carried out by 2,808,440 6 Patented Oct. 1., 19, 57

2 r us st rrin a mixtu e o t 2. -d y repyreh. water, and resin while the mixture is heated to thedcsired temperature. The dihydropyran may also be added to a Wa e -resi h c ha been preheated t t e es r d act o temp am It is desirable to carry out the hydrolysis reaction at temperatures between 50 C. and 95 C. Higher and lower temperatures are operative, but higher temperatures favor resinitlcation of the product, and lower temperatures req i ee te de ea p d The on periods necessary vary inversely with the reaction temper.- a ure- At th pre erred e t n t mp ra of 5 1 .C-, 7 to nve s on o .2. i y opy n t .5r yd e yvel eldehyd i obta n d in pe o ra ng f o t 5 m nutes- Pe ieds e r et h longer tha 15 minutes atthese temperatures result in reduced yields o 5.-.hyd exyvelera .dehy .e, d e to resihifieafiene o the advantages of our process over those of the prior art is that our process can be carried out at lower tempera- .thu a ei ih re hifieat eh a d less of h ehyde farm d.- fiz erhal c ol g of h reaction e se i u heeess yis des rab e t car y ou the hy y u ng 5 15 mole o Wat e mol c 3-d hys py e h about 1 to 3 parts by wcightof water per part of 2,3-dihydropyran. The use of smaller quantities of water tends to fe e es h fieet en; he use f ge quantifies en i un e essary expe s s h the Water m be ov d from the final product (LS-pentanediol) by distillation.

The amount of resin required for the hydrolysis may vary o e a wid ran e depen n on the ac d e t and capacity of the resin, The preferred resins are those hi h onta n sulfeh e i g up ch as Am rlit 1. -1. (Raha & H C pany) D w r 5 w Chem ea Company), ,Permut Q h Permutit P.3I Y).;. 11bfll R 2 (R hm ,8: H ss Comp y) v other resins of the sulfonated styrene, sulfonated phenolic e .snlf hated eeal pe h p r e amount o resin used is that corresponding to 80470 milliequivalents of sulfonic groups per mol of 2,3-dihydropyran. The resin is unaltered by the reaction under optimum reaction conditions and therefore may be readily recovered for reuse. The resin may be used continuously without change for prolonged periods of time in a continuous operation.

The S-hydroxyvaleraldehyde is preferably hydrogenated in the aqueous reaction medium following removal of the solution from the resin catalyst. The hydrolyzate occasionally is slightly acidic after removal of the resin catalyst; this acidity may be eliminated, if desired, by the addition of a very small quantity of dilute sodium hydroxide. The hydrogenation is carried out in the presence of a hydrogenation catalyst, preferably Raney nickel, at a pressure of 1000-2000 p. s. i., preferably 1500 p. s. i., and at a temperature of C. to 190 C. Generally, these conditions are maintained for about 3 hours after absorption of the hydrogen is complete, but this is not essential.

The following examples further illustrate the invention.

Example 1.A mixture of 168 g. of freshly distilled 2,3-dihydropyran, 540 g. of demineralized water, and g. of the acid form of Amerlite lR- (Rohin & Hass Co). is stirred vigorously while it is heated from 25 C. to 88 C. over a 15-minute period. (Amberlite IR-12O is a copolymer of styrene and divinylbenzene containing nuclear substituted sulfonic acid groups.) During this time the layer of 2,3-dihydropyran disappears completely. The mixture is then cooled to 30 C. within 8 minutes and the aqueous portion is filtered from the resin. The resin is washed three times with SO-ml. portions of water and the washings are added to the aqueous solution of the product. The aqueous solution of the 5-hydroxyvaleraldehyde formed is then made neutral to litmus by the careful addition of 3 to 5 drops of 5% aqueous sodium hydroxide. The neutral solution is mixed with 10.5 g. Raney nickel in a hydrogenation bomb and is heated to 150 C. with shaking under a hydrogen pressure of about 1500 p. s. i. These conditions are maintained for? hours after absorption of the hydrogen has stopped. The bomb is cooled, vented and emptied. The aqueous solution of the product is filtered and the water is removed by distillation at mm. pressure through a distillation column packed with Berl saddles. The residue of crude product is distilled in vacuo to give 178 g. (an 86% yield) of 1,5-pentanediol boiling at 1081l3 C. at 2.22.5 mm.

Example 2.-The procedure of Example 1 is followed, using the acid form of Dowex 50 in place of Amberlite IR-l20. A good yield of 1,5-pentanediol is obtained. Dowex 50 is a sulfonated polystyrene resin which is cross-linked with divinylbenzene. It is a synthetic cation exchange resin which contains nuclear sulfonic acid groups as the only cation active group. Dowex 50 is a strongly acidic resin with stability to strong acid, strong alkali and oxidizing agents even at elevated temperatures, and is operable over a wide pH range.

Example 3.168 g. of freshly distilled 2,3-dihydropyran is added over a 5-minute period to a vigorously stirred mixture of 80' g. of the acid form of A'mberlite IR-120 and 540 g. demineralized water preheated to 80 C. The temperature of the mixture is maintained at 75 80 C. for 5 minutes after the addition of the dihydropyran is complete. The mixture is rapidly cooled to 30 C. and the aqueous solution of the product is filtered from the resin. From this point on, the procedure of Example 1 is followed. 173 g. of 1,5-pentanediol is obtained: a yield of 83%.

Example 4.The procedure of Example 3 is followed, using the acid form of Permutit Q in place of Amberlite IR120. A good yield of 1,5-pentanediol is obtained. Permutit Q is a sulfonated styrene-type cationexchange resin having only (SO3H) exchange groups.

It will be understood that the hydrogenation step of the process may be carried out under different conditions than those described in the above examples. For instance, the aqueous solution of S-hydroxyvaleraldehyde may be brought to a pH of 4.33 by the addition of acetic acid or 4 other organic acid, after addition of the Raney nickel, and the mixture hydrogenated at C. at 1500 p. s. i. This procedure resulted in an 84% yield of 1,5-pentanediol, after the nickel was filtered off and the product distilled. Hydrogenation under the same conditions, except that the temperature was 190 C.,'gave a yield in excess of 85%.

If desired, the S-hydroxyvaleraldehyde formed by hydrolysis of the 2,3-dihydropyran may be isolated from the aqueous solution by distillation, and dissolved in methanol for the hydrogenation step. For instance, 102 g. of S-hydroxyvaleraldehyde was dissolved in 150 ml. of methanol and 6 g. of Raney nickel was added. Tributylamine was added to give a pH of 8.5, and the mixture was hydrogenated at 75 C. under a pressure of 1500 p. s. i. When hydrogenation was complete, theproduct was distilled to isolate 1,5-pentanediol in Yield. Trimethylamine or tribenzylamine may be used in place of tributylamine.

What we claim as our invention and desire to be secured by Letters Patent of the United States is:

1. A process of manufacturing S-hydroxyvaleraldehyde which comprises hydrolyzing 2,3-dihydropyran in the presence of the acidic form of an ion-exchange resin of the sulfonated type as a hydrolysis catalyst.

2. A process according to claim 1, in which the ionexchange resin is a copolymer of styrene and divinyl benzene, containing nuclear substituted sulfonic acid groups.

3. A process according to claim 1, in which the ionexchange resin is a sulfonated styrene-type cation-exchange resin having only (-SO3H) exchange groups.

4. A process according to claim 1, in which the hydrolysis is carried out at a temperature of from 75 C. to 90 C., for a period of from 5 to 15 minutes.

References Cited in the file of this patent UNITED STATES PATENTS MacLean et a1 Oct. 30, 1951 OTHER REFERENCES 

1. A PROCESS OF MANUFACTURING 5-HYDRIXYVALERALDEHYDE WHICH COMPRISES HYDROLYZING 2,3-DIHYDROPYRAN IN THE PRESENCE OF THE ACIDIC FORM OF AN ION-EXCHANGE RESIN OF THE SULFONATED TYPE AS A HYDROLSIS CATALYST. 